1. Technical Field
This invention relates to a disc cartridge having a magnetic disc or optical disc set rotatably in a cartridge case molded from a hard synthetic resin or in a flexible cartridge case. More particularly the invention relates to a cleaning sheet applied in the cartridge so that the sheet will be in sliding contact with the disc in the cartridge in operation for cleaning the disc surface.
2. Description of Prior Art
A magnetic disc cartridge comprises principally a cartridge case having a magnetic head inlet and an opening for passing through a drive shaft, a flexible magnetic disc set rotatably in the cartridge case, and cleaning sheets secured to the inside of the cartridge case.
A cleaning sheet used in magnetic disc cartridges has been made of a non-woven fabric of synthetic fiber, such as polyethylene terephthalate fiber or acrylic fiber, and secured to the inside of the cartridge case by means of, for instance, ultrasonic sealing or an adhesive.
The fibers constituting the conventional cleaning sheets were relatively large in size, such as about 15 to 30 .mu.m in diameter, and unable to perfectly sweep away and hold therein fine particles of dust and dirt adhering on the magnetic disc, especially those having a slight tackiness, and this has been a cause of error in the recording and reproducing operations of the magnetic disc.
The present invention has for its object to eliminate such defects of the prior art and to provide a disc cartridge which is guaranteed to perfectly clean the disc surface by use of specifically designed cleaning sheets to eliminate errors.